Field of the Disclosure
The present invention relates to the protection of stone countertops. In particular, examples of the present invention relate to a directional gas permeable protective covering for application to solid natural and man-made stone surface countertops to protect the stone countertop from damage during daily use in kitchens and bathrooms.
Overview of the Invention
Many consumers have adopted solid stone surface countertops made of natural or man-made stones such as, but not limited to: marble, granite, icestone, vetrazzo, limestone, quartz, soapstone, caesarstone, etc. These materials have become increasingly common in applications such as residential kitchens and bath countertops, tables, commercial tables and counters. With greater use of stones in these settings, there remains a need for maintenance on a regular basis due to the high porosity and high liquid absorbency of stone. These materials provide an increased level of beauty to the consumer, but come with upkeep requirements that are not enjoyable to some owners. Even with proper care, stone countertop materials often begin to show wear, damage, stains, etching, and the like. Stains may include surface markings from common organic or inorganic foods and liquids. Stains are relatively simple to remove. Etching, on the other hand, is discoloration and dulling of the stone from exposure to common organic or inorganic foods and liquids that have seeped through the stone surface and damaged the stone surface. In order to remove etched parts of stone, professional tradesmen in stone fabrication or restoration would need to polish the stone with abrasives utilizing a high-speed rotary polishing machine. A difference between staining and etching stone is often the amount of time organic or inorganic foods or liquids have been left on the surface of the stone.
Etching and staining stone countertops often occurs due to the porosity of the stone, which may have pores ranging from 25 um-260 um in diameter. Porous valleys and fissures (also known as “veins”) can span the entire piece of stone countertop, making it highly susceptible to staining and etching. In addition, certain known chemicals in food additives, food enhancers, drinking water, and common household cleaners have acids such as hydrogen chloride (HCl), which is damaging to many types of stone if left on the stone surface. The present invention provides a clear protective covering which protects stone countertops. Known clear protective films have significant negative impacts to stone countertop degradation due to the inability of the stone to outgas.
The presently disclosed protective film may possess the following identified qualities that are beneficial to a stone surface:                1. Breathability/Gas Permeability: The protective film should be gas permeable and allow for proper out-gassing and vapor release from the stone. Moisture migrating through the stone is called “Moisture Vapor Transmission”. Stone has an internal structure that is not absolutely solid. There are two physical properties found in stone: pores and capillary structures that are interconnected. The structure, size and orientation of these networks affect the degree which moisture can migrate by capillary action through the stone. If natural vapor transmission is not allowed to take place (as will be the case if covered by a non-gas permeable hard coated type film), the moisture gets trapped and can cause chemical, mineralogical, and structural changes within the stone. This action of decay in stone may take the form of pitting, cracking, discoloration, and flaking.        2. Heat Protection: The protective film should provide a means to disperse heat when it comes into direct contact with a heated object such as hot pots, hot pans, boiling water, hot oil splashed from cooking, etc. Excessive heat from direct contact being concentrated on a singular area can cause discoloration and cracking of the stone.        3. Proper Adhesion: Known adhesive structures are created to adhere to flat/smooth surfaces. Stone countertop surfaces, (which may seem flat and smooth in many instances), actually have fissures, pores, and irregularities that make traditional adhesive systems non-ideal. Uneven surfaces, air gaps, and visible distortions are created when these adhesives are used. These visual distortions are great detractions to the overall aesthetics of the stone material and in many cases prevent proper bonding to the stone surface material.        4. A protective film should provide protection against common household chemicals. Since stone counters are often used in bars, kitchens, and bathrooms, they will come into constant contact with household chemicals and acidic liquids such as lemon, lime, vinegar, coffee, wine, alcohol, calcium deposits in hard water, and surface cleaners. A stone surface protection film will come into contact with these same chemicals and liquids as well, hence the need for it to serve as an impenetrable barrier from them. A stone surface protection film should allow the stone surface material to outgas, yet be impervious to liquid and chemical penetration.        
Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of the protective film elements in the figures has been exaggerated relative to the dimensions of other elements such as the stone surface and pores in the stone surface to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.